How is DNA packaged inside cells?

• A. DNA is packaged as chromatin with no organized structure
• B. DNA is packaged as ribonucleoprotein complexes
• C. DNA is packaged as plasmids in the nucleus
• D. DNA is packaged as chromosomes that contain numerous segments of DNA called genes

Answer: (D)

DNA inside cells is organized into chromosomes, long DNA molecules wrapped around histone proteins to form chromatin. This structured packaging fits the genome into the nucleus and helps regulate which genes are expressed. During cell division, chromatin condenses further into visible chromosomes to ensure accurate separation of genetic material. So describing DNA as being packaged into chromosomes that contain many genes captures how the genome is organized and how it’s transmitted. Plasmids are extra-chromosomal DNA found mainly in bacteria and aren’t the standard way nuclear DNA is packaged in eukaryotic cells. Ribonucleoprotein complexes involve RNA, not DNA packaging. And saying there’s no organized structure ignores the well-established chromatin and chromosome organization.